Audience Cornucopia?

I think that whether you personally agree or disagree with a paper has nothing to do with your job as a tutor. A tutor besides the obvious writing-strength-assistance can assist with argument and form as well, but your personal objection only goes as far as playing the "devil's advocate." Being offended is a moral judgement, and teaching writing is almost pure rhetoric. We are entrapped in our writing by what society dictates as worthy subject material; within society itself hierarchies such as school dictate subjects as well. Language shapes our writing, society molds what we write about. The tutor's job relies specifically on the Language-bit.
When a student approaches with no argument at all, the tutor does not simply write it for them. The tutor persuades the writer to translate their own opinion, to take their own stance on subjects. If you want to argue content they already have, you're directly contradicting that mantra, "make better writers, not writing." The writer imagining their audience is an important component to their writing, but each individual has their own grasp on society's expectations in that capacity. If we were to strip others of their own cultural influence by asking them to reconsider their imagined audience, we would be missing the point of there even being writing to begin with.
Granted, sometimes a person writes with no conception of audience-cornucopia needs a little nudge of awareness, but I generally believe that if you have a problem with what someone's written about, and not how they've written it, you should just leave it alone, THAT'S ALL I'M TRYING TO SAY!!!